fit-columns-modify.js

// Modify fitColumns layout mode to not resize container
// and support percentage width items
var FitColumns = Isotope.LayoutMode.modes.fitColumns;
FitColumns.prototype._getContainerSize = function() {};

FitColumns.prototype.needsResizeLayout = function() {
  // don't trigger if size did not change
  var size = getSize( this.isotope.element );
  if ( this.isotope.size && size ) {
    return size.innerHeight !== this.isotope.size.innerHeight ||
      size.innerWidth !== this.isotope.size.innerWidth;
  } else {
    return false;
  }
};